Genuine question, not sarcasm. How does this work? As in, how is it different from an agent reading the code and inferring the result?

I had to install Playwright to get Claude Code to acknowledge a rendering issue when it verified that the data was in the DOM. Can this detect something from the served content in some new and novel way?

I'm dumb, might have missed it, only scanned the page looking for a heading that would explain and didn't see one, apologies if the page explains it and I missed it.

It can save tons of tokens compared with screen capture or reading the HTML directly. The downside is that we are still not able to handle complex JavaScript and CAPTCHA checks.